Conventional ionizers or precipitators comprise large and very specialized devices. These devices are intended for large industrial applications, for example a cement factory, and have high power requirements. Due to their large power requirements, the ionizers include separate high voltage power supplies and tend to be very bulky and costly to manufacture and maintain. The devices are typically designed as stand-alone units which are coupled to existing ventilation or heating and cooling equipment. For these reasons, known devices are not well-suited for commercial applications, such as office buildings, or residential or consumer use. Published European Patent Application No. 90850276.8 discloses one such device according to the prior art.
In an office building, the air circulation system includes a filter bank which comprises a matrix of filter modules. Each filter module typically has a mechanical filter element which traps particulate matter in the air before the air is circulated. The filter elements need to be replaced on a regular basis thereby incurring both maintenance and replacement costs. There is also a cost associated with the disposal of the used filter elements. For medical facilities, the filter elements are treated as hazardous biological waste and the disposal costs are significant. Furthermore, the air circulation fans must have the capacity to push the "dirty air" through the filter elements. For a typical office building this means large electric motors with a high horsepower output to drive the circulation fans, which further increases the cost of a conventional air conditioning installation.
There is also reason to believe that filter elements which have become contaminated may contribute to "sick building syndrome".
Accordingly, there is a need for an ionizer which is suitable for commercial and residential use. It is an object of the present invention to provide a modular ionizer which may be integrated with an existing heating or cooling duct in the heating and cooling equipment (HVAC) of a building. It is another object of the present invention to provide an ionizer with an integrated high voltage generator which is operated from conventional AC power and features low power consumption. It is a further object of the present invention to provide an ionizer which produces negligible amounts of ozone as a by-product of the ionization process. It is yet a further object of the present invention to provide a modular ionizer which is arranged with other ionizer modules to form an ionizer bank or matrix suitable for use in larger installations such as those found in residential condominiums, office buildings, medical facilities, laboratories, food processing plants, electronic assembly (i.e. "clean-room") plants, and manufacturing and industrial plants.